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Quick Verdict

If the existing exit device is sound and its series is on a kit list, retrofit it: an SDC LR100 kit for Von Duprin 98/99, Falcon or First Choice rails, a Sargent M56A for 80 Series and P Series, a Corbin Russwin CRMELR for ED5000/ED4000, an Accentra RMELR for 7100/7200 rim devices. Order a factory device (Von Duprin QEL, Sargent 56-, Corbin Russwin MELR, Adams Rite MLR or EL) on new openings, fire-rated openings and any device with worn chassis parts. Every ELR device still needs a power transfer, a regulated 24 VDC supply sized to its draw, and a control input from the access system or operator. Retraction is never a bypass of mechanical egress: the pushbar always opens the door from the inside, and the authority having jurisdiction (AHJ) rules on the final opening.

Factory ELR device or field retrofit kit: which should you order?

The decision turns on three facts readable off the door: series, length and fire rating.

Order a factory device when the opening is new, when the label on the device or door calls for fire exit hardware, or when the existing device has a cracked chassis, a worn latch or a bent rail. The Von Duprin QEL99EO rim device runs about $2,176 at NLS; it is Grade 1, exit only, hex key dogging, non-handed, and its QEL option is also built on fire-rated devices such as the QEL98EO-F.

Order a retrofit kit when the device is in good mechanical condition and the brand publishes a kit for that exact series. SDC LR100 kits install without removing the device from the door, and Corbin Russwin converts existing solenoid and mechanical ED5000/ED4000 devices to MELR with its kits.

A kit listed as non-fire rated on a labeled door, or a Sargent device built before 2006, sends you back to a full device. If the real question is whether the opening needs ELR at all or just an electrified outside trim, settle that first in our ELR vs electrified exit trim breakdown. For new work, start at the panic exit device category and filter by ELR option.

Which ELR options does each brand sell, factory and retrofit?

Each manufacturer names ELR differently; the prefix or suffix is what you order by.

Brand	ELR designation	Factory or retrofit	Example part	Order page
Von Duprin	QEL (quiet electric latch retraction)	Factory	QEL99EO rim, QEL9975EO mortise, QEL9957EO-F three-point	QEL99EO
Von Duprin	Modular QEL / QELX conversion	Retrofit	47447540 for 22 Series built after Jan. 1, 2022, non-fire rated	Panic exit device category
Sargent	56- prefix	Factory	56-8710 surface vertical rod, exit only	Panic exit device category
Sargent	M56A, 55-M56A, 55-R56A	Retrofit	M56AF, M56AE, M56AJ, M56AG for 80 Series and P Series	M56A kit
Corbin Russwin	MELR	Factory	ED5200 MELR, ED5200 MELR M92	Panic exit device category
Corbin Russwin	CRMELR	Retrofit	CMELR-36, CRMELR-38, CRMELR-48 for ED5000/ED4000	CRMELR kit
Accentra (Yale)	MELR / RMELR	Factory and retrofit	7100MELR 36; RMELR-36 and RMELR-48 for 7100, 7200, 7200M	Panic exit device category
Adams Rite	EL (solenoid), LR (solenoid), MLR (motor)	Factory	8800EL rim, 8600MLR concealed vertical rod	Panic exit device category
SDC	LR100 QuietDuo	Retrofit	LR100VDK, LR100FCK, LR100DMK, LR100FAK, -EM versions	LR100VDK

Von Duprin. QEL is the factory motor option across rim, mortise and vertical rod 98/99 devices. The 47447540 Modular QEL kit is for the 22 Series only, 36 in. or 48 in., built after January 1, 2022, and is non-fire rated. Prefix decoding (QEL, RX, LX, EO, -F) is covered in Von Duprin part numbers explained.

Sargent. The 56- prefix marks factory ELR; the 56-8710 is a Grade 1 surface vertical rod, UL 10C and UL 305 listed, sized E 32 in., F 36 in., J 42 in., G 48 in. The M56A kit (about $816 at NLS) contains the motor bracket assembly, motor controller and fasteners with ribbon wiring; match its suffix letter to the existing device size letter. The 55-R56A adds the motor bracket and push rail assembly plus the 55- switch, the choice for 80 Series devices whose push rail also needs replacing.

Corbin Russwin and Accentra. The ED5200 MELR uses a 36 in. bar for 30 to 36 in. doors (W048 for a 48 in. bar), a 4-1/2 in. minimum stile and a 3/4 in. throw latch. The CRMELR kit (about $1,049 at NLS) is a full rail assembly with controller and touchbar end cap, no switches and no latch. Accentra's RMELR-36 and RMELR-48 fit 7100(F), 7200 and 7200M(F) rim devices and are not available on openings under 30 in. wide.

Adams Rite. Narrow stile aluminum doors get the 8800EL solenoid rim device or the 8600MLR motorized concealed vertical rod. Series context sits in our Adams Rite 8800, 8400, 8600 and 8700 guide.

SDC. LR100VDK covers Von Duprin 98/99 and 33/35 rails, 36 in. to 48 in. (about $523 at NLS); LR100FCK covers First Choice 3600/3700; LR100DMK covers Falcon Dor-O-Matic 1590/1490; LR100FAK covers Falcon Dor-O-Matic 1790/1690. All mount inside the rail behind the access cover. The -EM versions move the controller board outside the rail to gain about 3/4 in. to 1 in. of space, the fix when a standard kit does not clear.

Order the factory device or kit from the row that matches the series stamped on the existing device.

What do motor and solenoid ELR actually draw, and why does it matter?

Current draw decides the supply, the wire gauge and whether two doors can fire at once. Published figures:

Device	Drive	Voltage	Retraction current	Holding current	Power behavior
Adams Rite 8800EL	Solenoid	12 or 24 VDC	1.5 A (12 V) or 0.6 A (24 V) inrush/hold	Same as inrush	Fail-secure, relocks on power loss
Adams Rite 8600MLR	Motor	24 VDC, 2 A supply required	850 mA	370 mA dogged	Fail-secure, defaults latched
Accentra 7100MELR / RMELR	Motor	24 VDC (BPS-24-1), 1 A per device	0.65 A max	0.2 A continuous	Returns to self-latching mechanical mode

Von Duprin specifies that QEL does not include the power transfer, the power supply or the control operator. The PS902 or PS914 with a 2RS, 4RL or 4R board is the minimum, and the -2RS board controls two ELR devices with a time delay between outputs, which matters on pairs. Low inrush lets QEL run on standard Schlage supplies once peak draw of every device is added up. SDC states no door sequencer is required for a pair of manual doors on a suitable supply.

Sizing method, battery backup and output boards are covered in how to choose an access control power supply. Order the supply from the power supply category in the same cart as the device.

What do signal switch and RX options report?

ELR moves the latch; switches report it. Order them with the device, not later.

• Von Duprin RX adds one internal SPDT switch that monitors the push pad. It reports to a security console or, with a horn, works as a single-door alarm. It is a signalling switch rated 2 A resistive maximum, never a load switch. The RXQEL99EO combines RX with QEL.
• Sargent 55- is a non-contact request-to-exit switch. The 55-M56A kit (motor kit plus 55- switch) and the 55-R56A push rail kit both carry it.
• Corbin Russwin M92 adds touchbar monitoring on the ED5200 MELR.
• CRMELR and plain M56A ship without switches: if the access panel needs a REX input to shunt the door position alarm, order the switch version.

Order the switch-equipped version of the kit or device whenever the panel expects a REX input.

How do you fill in an ELR order without a callback?

Every field is on the device, the door label or the schedule.

Ordering field	What to read on the existing device	Example
Brand and series	Center case or rail stamp	Von Duprin 99, Sargent 80 Series, Corbin Russwin ED5000
Device type	Rim, mortise, SVR or CVR	QEL99EO rim vs QEL9975EO mortise
Device length	Rail length or size letter	Sargent F (36 in.), Von Duprin 3 ft or 4 ft, Accentra 36 or 48
Fire rating	Label on door and device, "-F" suffix	QEL98EO-F; kits marked non-fire rated stay off labeled doors
Finish	Existing finish code	Match the rail and end cap finish
Function	EO, night latch, trim function	EO devices take no outside trim
Voltage and draw	Controller label or schedule	24 VDC, 1 A per Accentra MELR device
Switches	Panel input list	RX, 55-, M92
Date range	Manufacture date on the device	Sargent M56A: built after 2006; VD 47447540: 22 Series after Jan. 1, 2022

Power transfer is the item most often forgotten: put the electrified hinge or power transfer on the same order. Electrical connections belong to a qualified technician, and fire-rated ELR devices tied to a fire alarm system are wired as the AHJ requires.

Fill the table, then order the matching factory device or kit from the panic exit device category.

Common mistakes

1. Ordering an SDC LR100 kit by brand only: LR100VDK is Von Duprin 98/99 and 33/35, LR100FAK is Falcon 1790/1690.
2. Installing a kit listed as non-fire rated, such as the Von Duprin 47447540, on a labeled fire door.
3. Forgetting that QEL ships without power transfer, power supply or controller.
4. Sizing the supply on holding current. Size on retraction current of every device that can fire at once.
5. Using a standard LR100 where the rail is crowded instead of the -EM version with the external controller.
6. Wiring a load through the Von Duprin RX switch; it is rated as a signalling switch, 2 A resistive maximum.

FAQ

What is a motorized latch retraction kit? A field kit that adds a motor drive inside an existing exit device rail so an access system can retract the latch. SDC LR100, Sargent M56A, Corbin Russwin CRMELR and Accentra RMELR each fit named series only.

What is the difference between the Sargent M56A and 55-M56A latch retraction kits? Both retrofit the standard mechanical rail on 80 Series and P Series devices built after 2006 with a motor bracket assembly, motor controller and fasteners. The 55-M56A adds the 55- non-contact request-to-exit switch for the access panel.

Can the Von Duprin QEL work with a standard power supply? Von Duprin states QEL has a low inrush and can run on standard Schlage power supplies, with PS902/914 and a 2RS, 4RL or 4R board as the minimum. Add up the peak draw of every device on the supply first.

Is Adams Rite 8600 electric latch retraction fail-safe or fail-secure? The 8600MLR is configured fail-secure: on power loss it defaults to latched, and the pushbar still opens the door from inside. It needs 2 A at 24 VDC regulated and filtered power.

Next step

Read the brand, series, length and fire rating off the existing device, then order from the panic exit device category or go straight to the Sargent M56A motor kit, the SDC LR100VDK for Von Duprin 98/99 or the Corbin Russwin CRMELR kit. Orders placed by 3 p.m. ET ship the same day, and orders of $450 and up ship ground free. For a multi-door ELR package send the schedule to the quote desk; agencies can submit through government PO intake.